JPH09193072A - Optical fiber base material gripping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive base material gripping device which can simultaneously satisfy sufficient strength to support an optical fiber base material and accuracy for centering. SOLUTION: A base material gripping device is provided with an optical fiber base material support stand 20 having an optical fiber base material gripping hole opened in a U shape movable in the horizontal direction, two centering members which are arranged under the optical fiber base material support stand 20 and are oppositely opened and closed and a centering mechanism 30 having an opening mechanism to move the two centering members. The two centering members are formed in the same shape, and have a centering surface opening in a V groove shape having two vertical planes having an equal angle to a vertical plane passing through the opening-closing directional central axis, and the optical fiber base material support stand 20 and the centering mechanism 30 can move in the vertical direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for holding an optical fiber preform in an optical fiber manufacturing apparatus or the like.

[0002]

2. Description of the Related Art When drawing an optical fiber preform,
A gripping device for gripping the optical fiber preform is required. When manufacturing an optical fiber, first, a porous glass base material made of glass fine particles is manufactured, and then heat treatment is performed to manufacture a transparent high-purity glass base material, that is, an optical fiber base material.

FIG. 5 is a diagram for explaining the drawing process, and is a schematic view showing an example of an optical fiber preform supplying section in the drawing machine. In the figure, 51 is an optical fiber base material, 52 is a base material holding device, 53 is a base material holding device support bracket, 5
Reference numeral 4 is a drawing furnace, 55 is an optical fiber, and 56 is a feeder. The optical fiber preform 51 grasped by the preform grasping device 52 is heated and melted in the drawing furnace 54 to form the optical fiber 55.
Is drawn as. The feeder 56 moves the position of the base material holding device supporting bracket 53 and supplies the optical fiber base material 51 to the drawing furnace 54.

FIG. 6 is a detailed view showing an example of a conventional base material gripping device 52 used in FIG. Base material gripping device 52
Is constituted by a scroll chuck having three claws 58 having a hollow hole 57. The optical fiber preform 51 is
In the direction of the arrow in the figure, that is, the optical fiber preform 51 is inserted into the hollow hole 57 of the preform grasping device 52 from below the preform grasping device 52 and held by the claw 58. The claw 58 is manually opened and closed. Such a base material gripping device 52 has three claws 58.
Since the center of the optical fiber base material 51 is always constant, the optical fiber base material 51 is held at the center of the base material holding device 52, even if the outer diameter of the holding portion of the optical fiber base material 51 slightly varies. It does not deviate from the center of the drawing furnace 54 described in FIG.

[0005]

Recently, however, it has been desired that the optical fiber preform be made large in size from the viewpoint of productivity, and as a result, the optical fiber preform is made longer and has a larger diameter than before. The conventional method of gripping the optical fiber preform having such a large size and heavy weight as described above has a problem in workability and safety, which is not preferable. Therefore, a base material holding device 70 shown in FIG. 7 has been proposed as a large-sized base material holding device for an optical fiber that solves the above problems. The base material gripping device 70 has two claw members 71 and 72 that face each other and open and close. One claw member 71
Has a V-groove-shaped gripping surface provided with two vertical surfaces having an equal angle θ with respect to a vertical surface passing through the central axis in the opening / closing direction. The other claw member 72 has a gripping surface that is a vertical surface that is orthogonal to a vertical surface that passes through the central axis in the opening / closing direction. The base material gripping device 70 includes an opening / closing mechanism (not shown) that opens and closes the two claw members 71 and 72. The amount of movement of the opening / closing mechanism is the amount of movement of the claw member 71 relative to the amount of movement of the claw member 72. It is 1 / (sin θ) times.

The base material gripping device 70 has a claw member 71,
The optical fiber preform 73 can be moved and set in the horizontal direction, that is, in the horizontal direction in the state where 72 is opened. That is, it is not necessary to insert the optical fiber preform 71 unlike the conventional case, and the degree of freedom in gripping is large. Further, since the claw member supports three points, there is an effect that the center of the grasped optical fiber preform 71 does not change. By the way, the above-mentioned base material gripping device 70 has the following problems.
That is, the base material gripping device 70 simultaneously supports the heavy optical fiber base material 73 and performs centering. For this reason, the base material holding device 70 is required to have sufficient strength for supporting the optical fiber base material 71 and accuracy for centering at the same time, so that the base material holding device itself becomes expensive.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide an inexpensive preform holding device which simultaneously satisfies sufficient strength for supporting an optical fiber preform and accuracy for centering. Is.

[0008]

The present invention has the following means to solve the above problems.

An optical fiber preform holding device according to a first aspect of the present invention comprises an optical fiber preform support base provided with an optical fiber preform holding hole opened in a U shape that is movable in the horizontal direction, and the optical fiber preform support. An optical fiber preform holding device having a centering mechanism provided with two centering members arranged below a fiber preform support base to open and close in opposition to each other and an opening mechanism for moving the two centering members, The two centering members have the same shape and two vertical surfaces having an equal angle to a vertical surface passing through the central axis in the opening / closing direction, and have a V-groove-shaped centering surface. The optical fiber preform support and the centering mechanism are movable in the vertical direction.

The optical fiber preform holding device according to a second aspect of the present invention is characterized in that the optical fiber preform support and the centering mechanism are movable integrally in the vertical direction.

According to the optical fiber preform holding device of the first aspect of the present invention, since the optical fiber preform support base and the centering mechanism are independently provided, the optical fiber preform support base is used. The weight of the material can be supported and the optical fiber preform can be centered by the centering mechanism. Therefore, the optical fiber preform support has only to have sufficient strength to support the weight of the optical fiber preform, and its precision does not need to be specially considered. Further, the centering mechanism only needs to be manufactured with high precision, and its strength does not need to be specially considered.
As a result, it is possible to obtain an optical fiber preform holding device that is less expensive than a device that is sufficiently strong and accurate.

According to the optical fiber preform holding device of the second aspect of the present invention, the optical fiber preform support and the centering mechanism are integrally movable in the vertical direction. When the lens is moved in the vertical direction, the distance between the optical fiber preform support and the centering mechanism does not change. Therefore, even if the outer diameter of the optical fiber preform changes, for example, the centering position of the optical fiber preform does not change, so the center of the optical fiber preform does not change.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of an optical fiber preform holding device of the present invention will be described below in more detail with reference to the drawings. FIG. 1 shows an optical fiber preform holding device 1 of the present invention.
It is explanatory drawing which shows the principal part of the drawing process which used 0.
The optical fiber base material 1 gripped by the optical fiber base material gripping device 10 is heated and melted in the drawing furnace 2 to form the optical fiber 3
Is drawn as. The feeder 4 moves the position of the optical fiber preform holding device 10 and supplies the optical fiber preform 1 to the drawing furnace 2. The optical fiber preform holding device 10 is
The optical fiber base material support base 20, the centering mechanism 30, and the vertical moving base 40 that integrally supports the optical fiber base material support base 20 and the centering mechanism 30 are provided.

The optical fiber base material support base 20 includes a base material support plate 21 for supporting the optical fiber base material 1 and a support bracket 22 for mounting the base material support plate 21. Base material support plate 2
1 is a base material support plate 21 as shown in FIGS.
An optical fiber preform holding hole 23, which is opened in a U-shape for holding the optical fiber preform 1, is provided in the central portion of the. At the four corners of the lower surface of the base material support plate 21, there are provided moving rollers 24 composed of spherical rolls and their housings, and the base material support plate 21 moves forward and backward in the frame 25 of the support bracket 22 in the horizontal direction. It can be moved left and right. The bottom plate 26 of the support bracket 22 has sufficient strength to support the optical fiber preform 1, and is slightly larger than the optical fiber preform holding hole 23 of the preform support plate 21 at the center of the bottom plate 26. It has a rectangular opening 27.

The centering mechanism 30 disposed below the optical fiber preform support 20 has two centering members 30A and 30B and two centering members 30A and 3A as shown in FIG.
An opening mechanism 31 for moving 0B is provided. The two centering members 30A and 30B face each other in the horizontal direction (vertical direction in FIG. 3) and open and close. Centering members 30A, 30
B is a V-groove-centered centering member having the same shape and having two vertical surfaces of the same angle θ with respect to a vertical surface passing through the central axis in the opening / closing direction, and in the present embodiment 45 °. Face 31
It has A and 31B. Therefore, in this embodiment, the centering surfaces 31A and 31B form a square. Each centering surface 31A forming a square,
31B has a cylindrical rotating roll 32 as shown in FIG.
Is rotatably provided with respect to the central axis 33 so that the centered optical fiber preform 1 can freely move in the vertical direction. The movement of the centering members 30A and 30B is
This is performed by the opening mechanism 31 that moves the support shafts 34A and 34B of the centering members 30A and 30B.

A guide shaft 35 slidably supports the support shafts 34A and 34B. Reference numeral 36 is an open / close feed screw shaft. In the open / close feed screw shaft 36, the screw direction is reversed at the central portion, one of which is the left screw and the other of which is the right screw and has the same feed pitch. The nut at the end of the support shaft 34A meshes with the left screw of the open / close feed screw shaft 36, and the nut at the end of the support shaft 34B meshes with the right screw of the open / close feed screw shaft 36, so that the open / close feed screw shaft 36 moves in one direction. The centering members 30A and 30B can be opened or closed by rotating the centering members 30A and 30B. In FIG. 3, reference numeral 37 denotes a drive pulley which is rotationally driven by a drive motor (not shown).

A method of holding the optical fiber preform 1 by the above-described optical fiber preform holding device 10 will be described. The vertical moving table 40 is moved to arrange the optical fiber preform support table 20 and the centering mechanism 30 at a position corresponding to the length of the optical fiber preform 1 to be gripped. Next, the drive pulley 37 of the centering mechanism 30 is driven to move the centering members 30A and 30B in the opening direction. An optical fiber preform in which the centering members 30A and 30B are opened wider than the diameter of the optical fiber preform 1 and the expanding head 1A at the upper end of the optical fiber preform 1 is opened in the center of the preform support plate 21. Fit into the grip hole 23.
When the optical fiber preform 1 is vertically hung in this state, the optical fiber preform 1 becomes the centering member 30A of the centering mechanism 30,
Suspended through 30B.

After that, the optical fiber preform 1 is moved in the direction to close the distance between the centering members 30A and 30B so that the optical fiber preform 1 has a cylindrical rotation roll 32 with the centering surfaces 31A and 31B.
Centered on the center axis. Along with this centering, the base material support plate 21 supporting the upper end of the optical fiber base material 1 also moves horizontally in the frame 25 of the support bracket 22 back and forth and left and right to move the centering members 30A and 30B. By moving to the centering position, the centering of the optical fiber preform 1 is achieved. When centering the above optical fiber preform 1,
Since the movement amounts of the centering surfaces 31A and 31B of the centering members 30A and 30B are all the same, the center position of the optical fiber preform 1 is always constant regardless of the diameter of the optical fiber preform 1. Become.

[0019]

As described above, according to the optical fiber preform holding apparatus of claim 1 of the present invention, since it has the optical fiber preform support base and the centering mechanism, the optical fiber preform support is provided. The table can support the weight of the optical fiber preform, and the centering mechanism can center the optical fiber preform. Therefore, the optical fiber preform support has sufficient strength to support the weight of the optical fiber preform and does not require special consideration in accuracy. Moreover, the centering mechanism does not need to be manufactured with high precision and special consideration is required in terms of strength. As a result, it is possible to obtain an optical fiber preform holding device that is less expensive than a device that is sufficiently strong and accurate.

According to the optical fiber preform holding apparatus of the second aspect of the present invention, since the optical fiber preform support and the centering mechanism are integrally movable in the vertical direction, the optical fiber preform can be moved. When the lens is moved in the vertical direction, the distance between the optical fiber preform support and the centering mechanism does not change. Therefore, even if the outer diameter of the optical fiber preform changes, for example, the centering position of the optical fiber preform does not change, so the center of the optical fiber preform does not change.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a main part of a drawing process using an example of an embodiment of an optical fiber preform holding device of the present invention.

2A and 2B are a plan view and a front view of an optical fiber preform support base of the optical fiber preform holding device in FIG.

3 is a plan view of a centering mechanism of the optical fiber preform holding device in FIG. 1. FIG.

FIG. 4 is a plan view of a main part of the centering mechanism of FIG.

FIG. 5 is a schematic view showing an example of a conventional optical fiber drawing process.

FIG. 6 is a perspective view showing an example of a conventional optical fiber preform holding device.

FIG. 7 is a perspective view showing another example of a conventional optical fiber preform holding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber base material 2 Drawing furnace 3 Optical fiber 4 Feeder 10 Optical fiber base material holding device 20 Optical fiber base material support 21 Base material support plate 22 Support bracket 23 Optical fiber base material holding hole 30 Centering mechanism 30A, 30B Centering member 31 Opening / closing mechanism 31A, 31B Centering surface 36 Opening / closing feed screw shaft

Claims (2)

[Claims] 1. An optical fiber preform support base provided with a horizontally movable U-shaped opening for holding an optical fiber preform, and an optical fiber preform support base disposed below the optical fiber preform support face to open and close in opposition to each other. An optical fiber preform holding device having two centering members and a centering mechanism having an opening mechanism for moving the two centering members, wherein the two centering members have the same shape and open / close direction. The optical fiber preform support base and the centering mechanism are perpendicular to each other, having two vertical surfaces having an equal angle to a vertical surface passing through the central axis and having a centering surface opened in a V-groove shape. An optical fiber preform holding device, which is movable in any direction. 2. The optical fiber preform holding device according to claim 1, wherein the optical fiber preform support and the centering mechanism are movable integrally in the vertical direction.